Switching devices with a power FET for switching a current flowing through a load are known. The load is coupled between a working voltage terminal and the drain terminal of the power FET. One terminal of a series resistor is connected to the gate terminal of the power FET. The other terminal of the series resistor is connected to a control voltage for the power FET. A device for detecting a short-circuit current flowing through the power FET generates an output signal for switching off the power FET when a short-circuit is detected. The short circuit detector has a shunt resistor connected to the source terminal of the power FET and analyzes the voltage drop across the shunt resistor in order to measure the current.
Such arrangements are known, for example from U.S. Pat. No. 5,684,663 (Mitter). In such arrangements, the output signal indicating the short circuit is supplied to an analog driver circuit which switches off the FET within a minimum of time after the appearance of the above-mentioned output signal so that damage to the FET or other circuit components as a result of the short-circuit current can be avoided.